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Dendrochronologist
Studies tree rings to determine the age of trees and reconstruct past climates.
Did you know?
Methuselah, a bristlecone pine in California's White Mountains, is about 4,850 years old, one of the oldest known living non-clonal organisms.
How subjects help
- Biology: Understand why a tree grows a wide ring in a good year and a thin one in a dry year.
- Chemistry: Test the wood in each ring for chemical clues about past rainfall and temperature.
- Geography: Collect tree samples from different regions to build a map of past droughts.
- Mathematics: Match ring patterns between old and living trees to date wood to the exact year.
A famous name
A. E. Douglass: Founded dendrochronology, the science of dating wood by counting and matching tree rings.
Try it yourself: Read a tree's life story
- If you have a stump or photo, find the middle. Each pair of one light and one dark ring is one year of growth. Count from the middle to the bark to find the tree's age.
- Now use the ring card: find the widest and narrowest rings. Wide rings mean a good growing year; narrow ones mean a hard year, often a dry one.
- Which two years look like droughts? Which years were best?
- Write a short diary for the made-up tree: which years were good, which were hard, and what might have happened.
Dendrochronologists measure ring widths under a microscope and match patterns between many trees to date old wood and rebuild rainfall and climate records going back centuries.
Adapted from US National Park Service: It Was a Very Good Year (lesson plan).
Also try: Survey the litter on your street.
Known for it in
USA, Germany, UK, Sweden, Switzerland